Steinfeld was born on December 11, 1996, in the Tarzana neighborhood of Los Angeles, California, the daughter of Cheri (née Domasin), an interior designer, and Peter Steinfeld, a personal fitness trainer. She has an older brother, Griffin. Her paternal uncle is fitness trainer Jake Steinfeld, and her maternal grand-uncle is former child actor Larry Domasin. Her maternal first cousin, actress True O'Brien, appeared in a television commercial when Steinfeld was eight years old, inspiring her to try acting as well.
Steinfeld's father is Jewish. Her maternal grandfather was of half Filipino and half African-American descent. She was raised in Agoura Hills and later in Thousand Oaks, California, attending Ascension Lutheran School, Conejo Elementary, and Colina Middle School. She was home-schooled from 2008 until her high school graduation in June 2015.
Steinfeld began acting at the age of eight; she appeared in several short films, including in the role of Talia Alden in the award-winning She's a Fox. She made several television guest appearances and commercials. Steinfeld was chosen for the role of Mattie Ross in True Grit when she was 13. The film was released internationally in December, 2010; Richard Corliss of Time magazine called her performance one of the Top 10 Movie Performances of 2010 and wrote that Steinfeld "delivers the orotund dialogue as if it were the easiest vernacular, stares down bad guys, wins hearts. That's a true gift". Reviews from Roger Ebert, the Los Angeles Times, and Rolling Stone were also complimentary. The role earned Steinfeld a nomination at the 83rd Academy Awards for Best Supporting Actress; the Oscar went to Melissa Leo. In May 2011, five months after Grit was released, Steinfeld was chosen to be the new face of Italian designer brand Miu Miu.
Also in 2011, Steinfeld was cast at age 14 to play Juliet Capulet in a 2013 adaptation of Shakespeare's Romeo and Juliet. The role was originally intended for a 20-year-old actress; since there was some concern that she would be asked to appear nude in the film, its director explained that when Steinfeld was cast, the script was changed to make it "age-appropriate for a 14-year-old." The screenwriter added that the film's purity was important, and the main characters "don't make love until they have been married." The film was released in October 2013 to poor reviews in the United States and internationally. Steinfeld played Violet, one of the leads in the romance-drama Begin Again (formerly called Can A Song Save Your Life?). The film was given a limited release in the United States on June 27, 2014, grossing $134,064 on its opening weekend; it opened in wide release on July 11. It was re-released by The Weinstein Company on August 29. Steinfeld starred as Petra Arkanian in Ender's Game, a science-fiction action-adventure film based on the book by Orson Scott Card. The film was released on November 1, 2013. Paramount Pictures closed a deal in 2011 for the screen rights to the Cat Patrick novel Forgotten and announced that she would play London Lane in a project yet to be filmed as of 2015. In 2014, Steinfeld was announced to star as Min Green in a screen adaptation of Daniel Handler's romantic-comedy book Why We Broke Up, but the film has not yet gone into production.
She was cast as Eliza opposite Ender's Game co-star Asa Butterfield in the film adaptation of Ten Thousand Saints, which premiered on January 23, 2015, at the 2015 Sundance Film Festival. Steinfeld was originally cast to play the female lead in the 2015 film, For the Dogs, but was replaced by actress Emma Roberts. In spring 2014, Steinfeld narrated as the voice of Anne Frank for an exhibition on Frank at the Museum of Tolerance. In October, she was cast to star as Hadley in The Statistical Probability of Love at First Sight, based on the novel of the same name by Jennifer E. Smith. Steinfeld was announced in January 2015 as the star of the film adaptation of Carrie Pilby, the young adult novel by Caren Lissner. In March, Steinfeld was one of the voice actors for the English-language dub of the Japanese animated film When Marnie Was There. Steinfeld plays Anna alongside Kiernan Shipka as Marnie. Steinfeld stars in the music video for Taylor Swift's single "Bad Blood". The video premiered at the 2015 Billboard Music Awards ceremony on May 17, 2015.
In 2015, Steinfeld co-starred in Pitch Perfect 2, alongside Anna Kendrick, Rebel Wilson, and Elizabeth Banks, who also directed. She played some of her songs for a representative from Republic Records at an event in New York City, and the label signed her. In May, Republic Records announced the record deal and that Steinfeld was working on her first release.
In April 2015, Steinfeld was cast in a lead role in Break My Heart 1000 Times, based on the YA novel by Daniel Waters. Scott Speer is set to direct. In July 2015, Steinfeld and singer Shawn Mendes released an acoustic version of Mendes' single, "Stitches". The following month, Steinfeld released her debut single, "Love Myself", with Republic Records. Media outlets dubbed the song an "ode to masturbation".
Steinfeld's debut extended play, Haiz (the nickname used by her fans), was released in November 2015. Haiz was produced by Mattman & Robin and features co-writers Julia Michaels and Justin Tranter. The EP was released to mixed reviews from PopDust, Vulture and Nylon. In February 2016, Steinfeld released "Rock Bottom" as the second single in a new version featuring American funk pop band DNCE. Her single "Starving" was released in July 2016. The song is a collaboration with Grey featuring Zedd and became her biggest hit to date going platinum in Italy, New Zealand, Sweden, United Kingdom and the United States while also going double platinum in Australia and triple platinum in Canada.
Steinfeld played the lead role in The Edge of Seventeen, a coming-of-age comedy co-starring Blake Jenner, Woody Harrelson and Kyra Sedgwick, and written and directed by Kelly Fremon Craig. The film was released November 18, 2016, to positive reviews, and Steinfeld's performance was praised by critics and earned a Golden Globe Award nomination.
A second Pitch Perfect sequel was announced in June 2015. Steinfeld is confirmed to return for the third installment of the franchise. Steinfeld's new single "Most Girls" was released on April 28, 2017. Steinfeld signed on to star in the Bumblebee-centered Transformers film, which will take place before the rest of the film series, making the film a prequel.
On September 8, 2017, Hailee released a new single "Let Me Go" in collaboration with Swedish record producer Alesso featuring backup vocals from Florida Georgia Line and Republic Records songwriter Andrew Watt.Haiz (2015)